JPH0814703A - Refrigerant evaporator - Google Patents

Abstract

PURPOSE:To prevent a protrusion from being formed by a pipe connector member in relation to a refrigerant evaporator having a refrigerant-refrigerant heat-exchanging part in addition to a refrigerant evaporation part. CONSTITUTION:The height h2 of a refrigerant-refrigerant heat-exchanging part 8 is made lower as compared with the height h1 of a refrigerant evaporation part 7, and the refrigerant-refrigerant heat-exchanging part 8 is disposed on the side of the refrigerant evaporation part 7. By this method, a step part 11 is formed on one end side of the refrigerant-refrigerant heat-exchanging part 8, and a pipe connector member 12 and an expansion valve 5 are disposed in a space of the step part 11. As a result, the whole shape of a refrigerant evaporator can be arranged in a small-sized and compact structure, so that no protrusion is formed by the pipe connector member 12, and it also becomes easy to couple the evaporator to a cooling unit case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant evaporator having a refrigerant-refrigerant heat exchange section for improving cooling performance.
For example, it is suitable for use in an air conditioner for automobiles.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed a laminated refrigerant evaporator having a refrigerant-refrigerant heat exchange section (sub heat exchange section) for improving cooling performance in Japanese Patent Laid-Open No. 5-196321. . In the refrigerant evaporator 6 of the refrigeration cycle, as described in the above publication, in addition to the refrigerant evaporating section (main heat exchanging section) 7 for exchanging heat between the ordinary refrigerant and the evaporator, the evaporator described in the above publication has an evaporator. Refrigerant-refrigerant heat exchange section (sub heat exchange section) for exchanging heat between the refrigerant on the inlet side and the refrigerant on the evaporator outlet side to reduce the dryness of the refrigerant flowing into the inlet tank 7c of the refrigerant evaporation section 7. 8 are provided.

Due to the action of the refrigerant-refrigerant heat exchange section 8, the dryness of the refrigerant flowing into the inlet tank 7c of the refrigerant evaporation section 7 is greatly reduced so that the refrigerant in the inlet tank 7c is in a state close to a liquid single phase. With this configuration, when the refrigerant is distributed from the inlet tank 7c to the multiple refrigerant passages (tubes) 7a, the liquid refrigerant can be evenly distributed to the respective passages 7a. Moreover,
The inner surface of each passage (tube) 7a is covered with the liquid refrigerant, the heat transfer coefficient on the inner surface of each passage is improved, and these factors are combined to improve the cooling performance of the evaporator.

[0004]

By the way, in the prior art described in the above publication, a refrigerant inlet pipe into which a gas-liquid two-phase refrigerant from a pressure reducing means such as an expansion valve flows in, and a refrigerant which causes the vaporized gas refrigerant to flow out. A pipe connector member (generally referred to as a block joint) 12 for holding and fixing the outlet pipe is arranged laterally of the refrigerant-refrigerant heat exchange section 8.

Since the height of the pipe connector member 12 is sufficiently lower than the heights of the refrigerant evaporation portion 7 and the refrigerant-refrigerant heat exchange portion 8, the pipe connector member 12 has a refrigerant-refrigerant heat resistance as shown in FIG. It will protrude laterally from the side surface of the exchange part 8. Due to the presence of the protrusion by the pipe connector member 12, when the refrigerant evaporator 6 is housed in the case of the cooling unit and assembled, it becomes difficult to align the refrigerant evaporator 6 and the case of the cooling unit, and the evaporator assembly Since the assembling work becomes very troublesome, there was a problem that the assembling workability was significantly reduced.

The present invention has been made in view of the above points,
An object of the present invention is to provide a refrigerant evaporator in which a pipe connector member does not laterally protrude from a side surface of a refrigerant-refrigerant heat exchange section.

[0007]

In order to achieve the above object, the present invention employs the following technical means. According to the first aspect of the invention, the refrigerant evaporator (7) for exchanging heat between the refrigerant flowing in the refrigerant passage (7a) and the cooled fluid flowing outside the refrigerant passage (7a), and the refrigerant evaporator (7). Refrigerant-refrigerant heat exchange section (8) for exchanging heat between the refrigerant flowing into the inlet side of the refrigerant passage (7a) and the refrigerant flowing out from the outlet side of the refrigerant passage (7a) of the refrigerant evaporation section (7). Has and
The refrigerant passages (7a, 8a, 8b) of the refrigerant evaporating part (7) and the refrigerant-refrigerant heat exchanging part (8) are made of a thin metal plate (7).
b, 8g), the refrigerant-refrigerant heat exchange section (8) is formed to have a height lower than the height h1 of the refrigerant evaporation section (7), and the refrigerant evaporation section (7) side. And a step portion (11) is formed at one end of the refrigerant-refrigerant heat exchange section (8), and an inlet passage () through which the refrigerant flows into the refrigerant-refrigerant heat exchange section (8). 13a, 14
a) and a pipe connector member (12) having outlet passages (13b, 14b) for allowing the refrigerant to flow out from the refrigerant-refrigerant heat exchange section (8), and the pipe connector member (12)
At the side of the refrigerant evaporation section (7),
The technical means of being arranged in the step portion (11) on one end side of the refrigerant heat exchange portion (8) is adopted.

According to a second aspect of the present invention, in the refrigerant evaporator according to the first aspect, the refrigerant evaporation section (7), the refrigerant-refrigerant heat exchange section (8), and the pipe connector member (12) are provided. It is characterized by being integrally joined by brazing. According to a third aspect of the invention, in the refrigerant evaporator according to the first or second aspect, the inlet passage (13a, 14a) and the outlet passage (13b, 14b) of the pipe connector member (12) are respectively connected to the refrigerant- Passages (16a, 23a, 16) for connecting to the inlet side refrigerant passage (8a) and the outlet side refrigerant passage (8b) of the refrigerant heat exchange part (8).
c) (16b, 23b, 16d) is an end plate (16) of the refrigerant-refrigerant heat exchange section (8) on the refrigerant evaporation section side and an end of the refrigerant evaporation section (7) on the refrigerant-refrigerant heat exchange section side. Board (23)
It is characterized in that it is formed in.

According to a fourth aspect of the present invention, in the refrigerant evaporator according to any one of the first to third aspects, an expansion valve (5) for expanding the refrigerant is housed in the step portion (11). In this way, the pipe connector member (12) is directly connected. According to a fifth aspect of the invention, in the refrigerant evaporator according to any one of the first to third aspects, the expansion valve (5) for expanding the refrigerant is:
The expansion valve (5) is arranged so as to be located in the flow path of the fluid to be cooled of the refrigerant evaporating portion (7), and is connected to the pipe connector member (12) via a refrigerant pipe (28). It is characterized by being.

The invention according to claim 6 is the invention according to claims 1 to 5.
A cooling unit, characterized in that the refrigerant evaporator (6) according to any one of (1) to (4) is housed in a case (25, 26) divided into two. The reference numerals in parentheses of the above means indicate the corresponding relationship with the specific means described in the embodiments described later.

[0011]

According to the inventions of claims 1 to 6,
Due to the above technical means, the height (h2) of the refrigerant-refrigerant heat exchange section (8) is made lower than the height (h1) of the refrigerant evaporation section 7 in the stepped portion (11). Since the pipe connector member (12) is arranged, the member 12 can be arranged within the width dimension of the evaporator (6) including the refrigerant-refrigerant heat exchange section (8) and the refrigerant evaporation section (7). , Therefore evaporators (6)
The whole can be put together in an orderly rectangular shape without partial unevenness.

As described above, since the evaporator (6) can be gathered into a regular and orderly square shape without any unevenness, the evaporator (6) is inserted into the case (25, 26) of the cooling unit.
Cases (25, 26) for assembly work to store
And the evaporator (6) can be easily aligned, and the assembling work can be easily performed. According to experiments and studies by the present inventors, in the refrigerant-refrigerant heat exchange section (8), an outlet through which a refrigerant having a high degree of dryness (a large proportion of gas refrigerant) flowing out from the refrigerant evaporating section (7) flows. When the length of the side refrigerant passage 8b is increased, the refrigerant pressure loss is increased and the performance of the refrigerant evaporating portion 7 is deteriorated. However, in the present invention, the refrigerant-
The height (h2) of the refrigerant heat exchange section (8) is set to the refrigerant evaporation section (7).
Lower than the height (h1) of the outlet side refrigerant passage (8b)
Since it is possible to shorten the length, the problem of increased pressure loss in the outlet side refrigerant passage (8b) can be solved at the same time.

Further, since the pipe connector member 12 is disposed in the step portion 11, the evaporator 6 as a whole can be made compact.
It can be assembled in a compact size and contributes to downsizing of the cooling unit. In addition to the above effects,
In the invention of claim 2, since the refrigerant evaporating part (7), the refrigerant-refrigerant heat exchange part (8), and the pipe connector member (12) are integrally joined by brazing,
The entire evaporator including the pipe connector member (12) can be efficiently manufactured by integral brazing.

According to the third aspect of the present invention, the passages (16a, 23a, 16) are formed integrally with the end plate (16) of the refrigerant-refrigerant heat exchange section (8) and the end plate (23) of the refrigerant evaporation section (7).
c) (16b, 23b, 16d), the inlet passages (13a, 14a) and the outlet passages (13b, 14b) of the pipe connector member (12) and the inlet-side refrigerant passage (8) of the refrigerant-refrigerant heat exchange section (8). 8a), the outlet side refrigerant passage (8b) can be connected, and the passage connection structure can be simplified.

According to the fourth aspect of the invention, the expansion valve (5) can be arranged within the width dimension of the refrigerant-refrigerant heat exchange section (8) which does not require ventilation, so that the refrigerant evaporator ( When the fluid to be cooled (for example, air) is circulated with respect to 6), the expansion valve (5) does not become a flow resistance, and it is possible to increase the flow amount and reduce the fluid noise. Moreover, in the invention according to claim 4, the pipe connector member (1
Since both 2) and the expansion valve (5) are housed in the stepped portion (11), the entire evaporator 6 can be integrated into a more compact and compact body.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 4 shows a refrigeration cycle of an air conditioner for a vehicle to which the refrigerant evaporator of the present invention is applied. Reference numeral 1 denotes a compressor, an engine for a vehicle (not shown, driven through an electromagnetic clutch 2). Source). A condenser 3 cools the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 by exchanging heat with the air blown from a cooling fan (not shown),
It condenses.

Reference numeral 4 is a liquid receiver for accumulating the liquid refrigerant condensed in the condenser 3 and discharging only the liquid refrigerant to the downstream side of the cycle. Reference numeral 5 is a temperature-operated expansion valve constituting a pressure reducing means for the refrigerant. Reference numeral 6 is according to the present invention. It is a laminated refrigerant evaporator. The evaporator 6 includes a refrigerant evaporating part (main heat exchanging part) 7 for exchanging heat between the refrigerant flowing in the refrigerant passage 7a and the blast air for cooling (fluid to be cooled) flowing outside the refrigerant passage 7a, and the refrigerant. Refrigerant flowing into the inlet side of the refrigerant passage 7a of the evaporator 7 and the refrigerant evaporator 7
A refrigerant-refrigerant heat exchange section (sub heat exchange section) 8 for exchanging heat with the refrigerant flowing out from the outlet side of the refrigerant passage 7a.

Here, in the refrigerant-refrigerant heat exchange section 8,
Reference numeral 8a denotes an inlet side refrigerant passage through which a refrigerant flowing into the inlet side of the refrigerant passage 7a of the refrigerant evaporation portion 7 flows, and 8b indicates an outlet side refrigerant through which a refrigerant flows out from the outlet side of the refrigerant passage 7a of the refrigerant evaporation portion 7. Indicates a passage. On the other hand, the refrigerant evaporation unit 7 constitutes a refrigerant-air heat exchange unit in which the refrigerant absorbs heat from the blown air and evaporates.

Reference numeral 9 is a refrigerant passage having a minute cross section formed in a meandering shape between the inlet side refrigerant passage 8a of the refrigerant-refrigerant heat exchange portion 8 and the inlet portion of the refrigerant passage 7a of the refrigerant evaporation portion 7, and is generally a capillary. It acts as a decompression means called a tube. However, since the degree of decompression by the minute refrigerant passage 9 is set to be smaller than the degree of decompression of the expansion valve 5, the minute refrigerant passage 9 functions as an auxiliary depressurizing means, and the refrigerant-refrigerant heat exchange section 8 is provided. There is a difference in height between the refrigerant temperature of the inlet side refrigerant passage 8a and the refrigerant temperature of the outlet side refrigerant passage 8b, so that the heat exchange between the both passages 8a, 8b can be favorably performed.

The refrigerant evaporating portion 7, the refrigerant-refrigerant heat exchange portion 8 and the minute refrigerant passage 9 are formed by a laminated structure of thin metal plates, and the specific structure thereof is basically disclosed in Japanese Patent Laid-Open No. 5-1.
Since it may be the same as that of Japanese Patent No. 96321, the outline of the laminated structure will be described below with reference to FIGS. 1, 2 and 3. In the refrigerant evaporating section 7, a thin metal plate 7b, specifically, a double-sided surface in which a brazing material is clad on both surfaces of an aluminum core material. After molding the clad material into a predetermined shape, stacking a large number of these as two sets,
A large number of refrigerant passages 7a are formed by joining by brazing.
(See FIGS. 1 and 2) are formed in parallel.

The plurality of refrigerant passages 7a are U-shaped so that each of them makes a U-turn upward, and an inlet side tank portion 7c and an outlet side tank are provided in the lower portion of the passage formed by a set of the two metal thin plates 7b. The portion 7d is partitioned and the inlet and outlet of each U-shaped refrigerant passage 7a are mutually cored at the lower portion of the passage at the openings of the inlet-side tank portion 7c and the outlet-side tank portion 7d. It is designed to communicate in the width direction.

Here, in FIGS. 1A and 2, the front side in the direction perpendicular to the paper surface is the inlet side tank portion 7c, and the back side in the direction perpendicular to the paper surface is the outlet side tank portion 7d. Further, in the refrigerant evaporating section 7, corrugated fins (fin means) 10 are joined to the gaps between the outer surfaces of the adjacent refrigerant passages 7a to increase the heat transfer area on the air side.

On the other hand, also in the refrigerant-refrigerant heat exchange section 8,
A thin metal plate 8g, specifically, a double-sided clad material in which a brazing material is clad on both sides of an aluminum core material is formed into a predetermined shape, and a large number of these are laminated and joined by brazing to form a laminated structure of a large number of these. The inlet side refrigerant passages 8a and the outlet side refrigerant passages 8b are alternately formed between the metal thin plates 8g.

FIG. 5 shows the above-described refrigerant evaporation unit 7 and refrigerant-
The refrigerant passage configuration of the refrigerant heat exchange section 8 is schematically shown.
In the refrigerant passage in the figure, the shaded portion X indicates a liquid refrigerant,
A portion Y without hatching indicates a region of the gas refrigerant. Note that FIG.
In order to facilitate understanding, the inlet-side tank portion 7c and the outlet-side tank portion 7d of the refrigerant evaporating portion 7 are connected to the linear refrigerant passage 7
Although it is arranged at both ends of a, as shown in FIGS. 1 (a) and 2, both tank parts 7c and 7d are actually U-shaped.
They are arranged adjacent to each other in the air flow direction below the turn-shaped refrigerant passage 7a. Further, in FIG. 5, the minute refrigerant passage 9 is illustrated as a throttle shape for convenience.

By the way, as clearly shown in FIG. 1, the height h2 of the refrigerant-refrigerant heat exchange section 8 is lower than the height h1 of the refrigerant evaporation section 7 (for example, h1 = 300 mm) ( For example, h2 = 250 mm). Therefore, when the refrigerant-refrigerant heat exchange section 8 is arranged on the side of the refrigerant evaporation section 7, if the lower portions of both are aligned at the same height, the upper section of the refrigerant-refrigerant heat exchange section 8 is arranged. The step portion 11 is formed on (one end side).

A pipe connector member 12 is disposed in the step portion 11, and the pipe connector member 1
Reference numeral 2 is a pipe connection for an inlet passage through which the refrigerant flows into the inlet-side refrigerant passage 8a of the refrigerant-refrigerant heat exchange section 8 and an outlet passage through which the refrigerant flows out from the outlet-side refrigerant passage 8b of the refrigerant-refrigerant heat exchange section 8. Is. In this example, as shown in FIG. 2, the pipe connector member 12 has a rectangular parallelepiped first shape formed by cutting or die casting a metal such as aluminum.
Block joint 13 and a second block joint 14 formed by cutting or die-casting a metal such as aluminum in the same manner and having a shape in which one corner of a rectangular parallelepiped is cut off obliquely.

Then, this second block joint 1
A block-type temperature-operated expansion valve 5 is arranged on the front side of 4 (the inlet side in the air flow direction). The block-type expansion valve 5 has a well-known configuration in which a temperature sensitive cylinder 5a portion (see FIGS. 4 and 5) is integrally incorporated. Reference numeral 15 is a connection plate of the pipe connector member 12, which is also formed by cutting or die casting a metal such as aluminum into a rectangular plate shape.

Of the refrigerant-refrigerant heat exchange section 8, only the end plate 16 on the refrigerant evaporation section 7 side is formed to have the same height as the height h1 of the refrigerant evaporation section 7, and the upper portion of the end plate 16 is formed. The first block joint 13 is integrally brazed. Here, the first block joint 13
The refrigerant inlet hole 13a and the refrigerant outlet hole 13b are connected to the refrigerant inlet hole 16a and the refrigerant outlet hole 16b at the upper portion of the end plate 16, respectively, so that the both 13 and 16 are integrally brazed. FIG. 3 shows the refrigerant evaporator 6 in which the first block joint 13 is integrally brazed.

At the ends of the refrigerant inlet hole 13a and the refrigerant outlet hole 13b of the first block joint 13, a pipe portion 13c protruding toward the second block joint 14 is provided.
13d (see FIG. 3) is formed, and this pipe portion 1
By fitting the refrigerant inlet hole 14a and the refrigerant outlet hole 14b of the second block joint 14 into the 3c and 13d, respectively, the refrigerant inlet hole 13a and the refrigerant outlet hole 13b of the first block joint 13 and the second The refrigerant inlet hole 14a and the refrigerant outlet hole 14b of the block joint 14 communicate with each other.

The above-mentioned both 13, 14 pass the one bolt 17 shown in FIG. 2 through the bolt through hole 14e of the second block joint 14 and the female screw 13e of the first block joint 13 (see FIG. )) Is screwed in and fixed integrally. Here, the refrigerant inlet hole 13a and the refrigerant outlet hole 13b are the pipe portion 13
A seal material (not shown) made of an elastic material (rubber or the like) such as an O-ring is arranged on the outer peripheral sides of the c and 13d to prevent the refrigerant from leaking.

In the second block joint 14,
The refrigerant inlet hole 14a and the refrigerant outlet hole 14b are each bent at a right angle, and a refrigerant inlet pipe portion 14c and a refrigerant outlet pipe portion 14d are formed on the end surface of the second block joint 14 so as to project therefrom. Further, the second block joint 14 and the temperature actuated expansion valve 5
The three members of the connection plate 15 are integrally fastened and fixed with two bolts 18.

Here, in the connection plate 15, the high pressure side liquid refrigerant pipe 19 in which the liquid refrigerant from the liquid receiver 4 of FIG. 4 flows and the low pressure side gas refrigerant pipe 20 in which the gas refrigerant that has finished evaporation in the evaporator 6 flows. , And the high pressure side liquid refrigerant pipe 19 is connected to the inlet of the liquid side passage 5b of the expansion valve 5, and the low pressure side gas refrigerant pipe 20 is connected to the outlet of the gas side passage 5c of the expansion valve 5. Connected. A sealing material (not shown) made of an elastic material (rubber or the like) such as an O-ring is also arranged on both of these connecting portions to prevent the leakage of the refrigerant.

The liquid side passage 5b of the expansion valve 5 is provided with a valve body (not shown), and the gas side passage 5c is provided with the temperature sensing cylinder 5a for sensing the temperature of the circulating gas refrigerant therein. The valve body controls the valve opening degree (refrigerant flow rate) so that the superheat degree of the refrigerant at the outlet of the evaporator becomes a predetermined value according to the gas refrigerant temperature sensed by the temperature sensing cylinder 5a and the low pressure side refrigerant pressure. To do.

The outlet of the liquid side passage 5b of the expansion valve 5 (downstream of the valve body) is connected to the refrigerant inlet pipe portion 14c of the second block joint 14, and the inlet of the gas side passage 5c of the expansion valve 5 is connected to the first side. The refrigerant outlet pipe portion 14d of the second block joint 14 is hermetically connected to each other with seal members 21 and 22 made of an elastic material (rubber or the like) such as an O-ring interposed therebetween.

On the other hand, in the refrigerant evaporating portion 7, two protruding portions 23a and 23b projecting inward are integrally formed above the end plate 23 on the refrigerant-refrigerant heat exchange portion 8 side. The two overhang portions 23a and 23b form a refrigerant passage with the end plate 16 described above. Then, one end of the first overhanging portion 23a has a refrigerant inlet hole 16a of the end plate 16 and a refrigerant inlet hole 13a of the first block joint 13 through the refrigerant inlet hole 16a.
The other end communicates with the inlet 8c of the refrigerant inlet side passage 8a of the refrigerant-refrigerant heat exchange section 8 through another refrigerant inlet hole 16c of the end plate 16.

Further, one end of the second overhanging portion 23b has an end plate 1
No. 6 through the refrigerant outlet hole 16b communicates with the refrigerant outlet hole 13b of the first block joint 13, and the other end is the end plate 1
It is adapted to communicate with the outlet 8d of the refrigerant outlet side passage 8b of the refrigerant-refrigerant heat exchange section 8 through another refrigerant outlet hole 16d of No. 6. On the other hand, in the refrigerant-refrigerant heat exchange section 8, an outlet 8e of the inlet side refrigerant passage 8a and an inlet 8f of the refrigerant outlet side passage 8b are formed in the lower part thereof. The inlet 8c and outlet 8e of the inlet side refrigerant passage 8a and the inlet 8f and outlet 8d of the refrigerant outlet side passage 8b communicate with each other in the core width direction at their own openings. An inlet side refrigerant passage 8a is formed from the upper inlet 8c to the lower outlet 8e, and the lower inlet 8f to the upper inlet 8d.
The outlet side refrigerant passage 8b is formed toward the.

A refrigerant inlet hole 16e and a refrigerant outlet hole 16f are formed in the lower portion of the end plate 16 described above, and the minute refrigerant passage 9 is formed between the end plate 16 and the end plate 23. Cage (not shown in FIG. 2), the fine refrigerant passage 9
The inlet side is communicated with the refrigerant inlet hole 16e, and the outlet side is communicated with the inlet tank portion 7c of the refrigerant evaporator 7. Further, the inlet 8f of the refrigerant outlet side passage 8b communicates with the outlet side tank portion 7d of the refrigerant evaporator 7 through the refrigerant outlet hole 16f.

Therefore, the refrigerant flowing out from the outlet 8e of the inlet side refrigerant passage 8a next passes through the minute refrigerant passage 9 and then flows into the inlet side tank portion 7c of the refrigerant evaporation portion 7, from which the refrigerant evaporation portion 7 Each refrigerant passage 7a flows in a U-turn shape and then gathers in the outlet side tank portion 7d. The refrigerant collected in the outlet side tank portion 7d is the refrigerant outlet hole 16 formed in the lower portion of the end plate 16 of the refrigerant-refrigerant heat exchange portion 8.
It is designed to flow into the inlet 8f of the outlet side refrigerant passage 8b via f, and flow upward from the inlet 8f through the outlet side refrigerant passage 8b to reach the upper outlet 8d.

In the refrigerant-refrigerant heat exchange section 8, the inlet-side refrigerant passages 8a and the outlet-side refrigerant passages 8b are alternately formed on both front and back sides of a thin metal plate 8g laminated. From the outlet 8g of the outlet side refrigerant passage 8b, the refrigerant flows from the piping connector member 1
It flows to the 2 side. In FIGS. 1 to 3, reference numeral 24 denotes an end plate of the refrigerant evaporating portion 7 on the side opposite to the refrigerant-refrigerant heat exchange portion 8. Further, in FIG. 1, reference numerals 25 and 26 denote a resin upper case and a lower case, respectively, of a cooling unit of an automobile air conditioner, which is an evaporator 6 composed of a refrigerant evaporator 7 and a refrigerant-refrigerant heat exchanger 8, and further, The expansion valve 5, the pipe connector member 12 and the like integrated with the evaporator 6 are housed. After housing the evaporator 6, the upper and lower cases 25 and 26 are assembled together by connecting their respective end surfaces with a number of fittings 27.

Next, the operation of the first embodiment having the above structure will be described. Since the operation of the refrigerant evaporator 6 is basically the same as that of JP-A-5-196321,
A detailed description is omitted, and the operation of the characteristic portion will be described. As understood from FIG. 1A, the expansion valve 5 is within the range of the width dimension of the refrigerant-refrigerant heat exchange section 8 which does not need to be ventilated. Since it is arranged in the range of the width dimension of the stepped portion 11, in other words, when the air is blown to the refrigerant evaporator 6 as indicated by an arrow Z in FIG. There is no resistance, and it is possible to increase the amount of air flow and reduce the noise of air flow.

Further, according to the experiments and studies by the present inventors,
In the refrigerant-refrigerant heat exchange section 8, when the length of the outlet side refrigerant passage 8b (see FIG. 5) through which the refrigerant having a high degree of dryness (the ratio of the gas refrigerant is large) flows becomes long, the refrigerant pressure loss increases,
Since the performance of the refrigerant evaporation portion 7 is deteriorated, the outlet side refrigerant passage 8
It has been found that it is preferable to set the length of b to 250 mm or less.

On the other hand, the height h1 of the refrigerant evaporator 7 is 250 m.
In some cases, it is necessary to design it to be m or more. However, in the present invention, the height h2 of the refrigerant-refrigerant heat exchange section 8 can be made lower than the height h1 of the refrigerant evaporation section 7 to be 250 mm or less, so that the pressure loss in the outlet side refrigerant passage 8b increases. That problem can be solved at the same time. Further, the height h2 of the refrigerant-refrigerant heat exchange section 8 is set to the height h of the refrigerant evaporation section 7.
Since the pipe connector member 12 and the expansion valve 5 portion are arranged in the step portion 11 formed to be lower than 1, these members 5 and 12 are connected to the refrigerant-refrigerant heat exchange portion 8 and the refrigerant evaporation portion 7.
The evaporator 6 can be arranged within the width dimension (see FIG. 1 (a)), so that the entire evaporator 6 can be gathered into a regular rectangular parallelepiped shape without partial unevenness.

In this way, the evaporator 6 can be put together in an orderly and substantially rectangular parallelepiped shape without any unevenness, so that FIG.
(A), when performing the assembling work for housing the evaporator 6 in the upper and lower cases 25 and 26 shown in FIG. 6A, the upper and lower cases 25 and 26 can be easily aligned with the evaporator 6. , The assembling work can be easily performed. Further, since the pipe connector member 12 and the expansion valve 5 portion are arranged in the step portion 11, the entire evaporator 6 can be integrated into a small and compact size, and a cooling unit of an air conditioner for a vehicle can be obtained. The size can be reduced, and the cooling unit can be easily installed in a narrow space inside the vehicle.

(Second Embodiment) As shown in FIG. 7, the expansion valve 5 is not directly connected to the second block joint 14 of the pipe connector member 12, but the expansion valve 5 is connected to the front surface of the air flow path of the refrigerant evaporator 7. At the position, the outlet portion of the pipe 28 through which the gas-liquid two-phase refrigerant flows downstream of the expansion valve 5 and the inlet portion of the low pressure side gas refrigerant pipe 20 are connected to the refrigerant inlet pipe 14c of the second block joint 14 and the refrigerant outlet. The pipes 14d are connected to each other.

According to this second embodiment, the installation of the expansion valve 5 causes a problem that the ventilation resistance of the air flow path of the refrigerant evaporating section 7 increases, but as the expansion valve 5, the temperature sensitive cylinder 5a is provided outside. The usual low-cost type to be installed can be used. It is needless to say that the temperature sensitive cylinder 5a is arranged so as to be in thermal contact with only the low pressure side gas refrigerant pipe 20 and not to contact with the high pressure side liquid refrigerant pipe 19.

[Brief description of drawings]

1A is a front view showing a first embodiment of the present invention, FIG.
(B) is the side view.

FIG. 2 is an exploded perspective view of the refrigerant evaporator of FIG.

3 (a) is a front view showing a portion integrally joined by brazing in the refrigerant evaporator of FIGS. 1 and 2, and FIG. 3 (b) is a side view thereof.

FIG. 4 is a circuit diagram of a refrigeration cycle to which the refrigerant evaporator of the present invention is applied.

FIG. 5 is a schematic diagram schematically showing a refrigerant passage structure in the refrigerant evaporator of the present invention.

FIG. 6A is an exploded perspective view of the refrigerant evaporator and the cooling unit case before assembling, and FIG. 6B is a sectional view showing an outline of the arrangement structure after the assembling.

FIG. 7A is a front view showing a second embodiment of the present invention,
(B) is the side view.

FIG. 8 is a front view of a conventional refrigerant evaporator.

[Explanation of symbols]

 5 Expansion valve 6 Refrigerant evaporator 7 Refrigerant evaporation part 7a Refrigerant passage 8 Refrigerant-refrigerant heat exchange part 8a Inlet side refrigerant passage 8b Outlet side refrigerant passage 11 Stepped portion 12 Piping connector member 13 First block joint 14 First block joint 15 Connection plate 16, 23 End plate

Claims (6)

[Claims] 1. A refrigerant evaporating part for exchanging heat between a refrigerant flowing in the refrigerant passage and a fluid to be cooled flowing outside the refrigerant passage, and a refrigerant flowing into an inlet side of the refrigerant passage of the refrigerant evaporating portion.
A refrigerant-refrigerant heat exchange part for exchanging heat with the refrigerant flowing out from the outlet side of the refrigerant passage of the refrigerant evaporation part, and the refrigerant passages of the refrigerant evaporation part and the refrigerant-refrigerant heat exchange part are laminated of metal thin plates. The refrigerant-refrigerant heat exchange section is configured to be lower than the height of the refrigerant evaporation section and is disposed laterally of the refrigerant evaporation section, and one end side of the refrigerant-refrigerant heat exchange section is formed. And a pipe connector member having an inlet passage through which the refrigerant flows into the refrigerant-refrigerant heat exchange portion and an outlet passage through which the refrigerant flows out from the refrigerant-refrigerant heat exchange portion. The member is arranged in the step portion at one end side of the refrigerant-refrigerant heat exchanging part, on the side of the refrigerant evaporating part, the refrigerant evaporator. 2. The refrigerant evaporator according to claim 1, wherein the refrigerant evaporation section, the refrigerant-refrigerant heat exchange section, and the pipe connector member are integrally joined by brazing. 3. A passage for connecting an inlet passage and an outlet passage of the piping connector member to an inlet-side refrigerant passage and an outlet-side refrigerant passage of the refrigerant-refrigerant heat exchange portion, respectively, the refrigerant-refrigerant heat exchange portion. The refrigerant evaporator according to claim 1 or 2, wherein the refrigerant evaporator is formed on an end plate on the refrigerant evaporation part side and an end plate on the refrigerant-refrigerant heat exchange part side of the refrigerant evaporation part. 4. The expansion valve for expanding the refrigerant is directly connected to the pipe connector member so as to be housed in the step portion, according to any one of claims 1 to 3. Refrigerant evaporator described. 5. An expansion valve for expanding the refrigerant is arranged so as to be located in a flow path of a fluid to be cooled of the refrigerant evaporation section, and the expansion valve is provided to the pipe connector member via a refrigerant pipe. The refrigerant evaporator according to any one of claims 1 to 3, wherein the refrigerant evaporator is connected. 6. A cooling unit, wherein the refrigerant evaporator according to claim 1 is housed in a case divided into two parts.